Heavy housings, cumbersome brackets, heavy ladders required, and tricky field of view requirements will cause difficulties no matter the camera manufacturer, because of the install location or complexity of the camera technology.
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I would say from my experience, the most difficult part of any camera install is simply non ideal mounting surfaces. I've had no issue installing any of the multi-sensor cameras once the main mount is attached. The Axis P3707 was pretty easy to install on a new build. We told the electrician where to place the ceiling electrical box and it was fairly straight forward. If you have EIFS without plywood or steel building with thin siding, that makes the install take much longer with a heavier camera.
If you are up in the air and are trying to install multi-sensor cameras or PTZs from a ladder, then that would be poor planning as you should be on a lift. I'm not sure if anyone does but anything is more difficult using an extension ladder.
I won't comment on LPR setups as the difficulty is really in the pre-planning and final calibration.
Perhaps there should be an article about what takes the longest to install.
I forgot, the P3707 would be much easier if there was motorized zoom, but I believe that's coming soon.
